Solving the Car-Sequencing Problem in Constraint Logic Programming

CHIP is a new constraint logic programming language combining the declarative aspect of logic programming with the efficiency of constraint manipulation techniques. In the present paper, we show an application of CHIP to the car-sequencing problem which occurs in assembly line scheduling in car manufacturing. This problem is highly combinatorial and has been presented recently as a "challenge" lor Artificial Intelligence (Al) systems. We present the approach taken to solve this problem in CHIP and give some computational results for different configurations. lt is shown that CHIP provides not only the flexibilitywhich can be expected from an Altoolby simplitying greatly the problem statement but also the efficiency which allows to solve large assembly line problems. This efficiency comes lrom the ability of CHIP to use numerical and symbolic constraints to prune the search space very early. 2